CLINICAL DIAGNOSTICS IN CAPTIVE REPTILES

In clinical diagnostics it is of importance for the veterinarian to know something about the species he is dealing with.

This reminds me of Alice in Wonderland when the Queen asked her "Have you seen the Mock Turtle yet?''. ''No'' said Alice, ''I don't even know what a Mock Turtle is". "It is the thing the Mock Turtle soup is made from" said the Queen.

Happily, about 130 years later, turtles are no longer indicated as "things" and the habit of making soup of them is on the verge of extinction. It is nice to realise oneself here, in front of this audience, that the protection of animals started in England. In the early decades of the past century a law was accepted to protect asses. Roaring laughter exclaimed in the House of Commons when someone said "imagine in future we will protect dogs". Nowadays we protect the most curious creatures like reptiles as well. This is the result of an amazing and highly appreciated development broadening our views to include the so-called lower animals. Let us return to reptiles.

To the knowledge of diseases in reptiles the recent recognition of the unique, emotional value of living reptiles, is an essential progress in the respect for life. It is not only the species, but also the individual live animal, or even more, the individual pet animal which may be recognisably ill and thus alarm the owner, who will then consult the veterinary surgeon.

There is an extremely wide and vague range of events before an owner recognises whether an animal is ill or not. Tortoises and terrapins roaming relatively free in the garden or a pond may normally disappear for days. It then may take quite some time before an owner realises himself that he has not seen the animal and starts to look for his pet, possibly to find that it hides because it is ill. In other cases the onset of an acute disease may be noted within hours.

In the course of my paper I will try to indicate which signs are of importance to the owner, and how the veterinarian can work from this and come to a clinical diagnosis. We can try to realise ourselves what the restrictions are that the veterinarian is confronted with, and in consequence what the value is of a clinical diagnosis.

How can the owner contribute to clinical diagnosis?

For a vet, the contribution of the owner, who knows the normal behaviour of his animals, is essential. The better the owner's description is, the better the veterinarian can do his part of the job. It makes an enormous difference whether an owner comes in exclaiming "Oh, doctor my tortoise is so terribly ill, can you cure it" - this opens the complete world of possible diseases to the mind of the animal doctor, with only little chance that the appropriate thought will emerge. If however, the owner explains that the animal has been outside on a grassy area, with several others, that new animals which were found, have been brought in by kind and concerned people, that the animal has lost weight over some weeks and has shown some episodes of diarrhoea, then the mind of the veterinarian will be directed towards intestinal disturbances and there is a fair chance that a probable diagnosis of endoparasitism will be made and an exact clinical diagnosis, of an infection with the protozoan flagellate,Hexamitaparva forinstance. These two examples illustrate that the owner contributes essentially to the quality of veterinary clinical diagnostics. However, the veterinarian may not rely completely on the observations of the owner. I remember two separate cases where snakes were brought in with problems of the skin. In one there was a blackish discoloration of the margins of the ventral scales. This proved to be a prolonged shedding of the skin, in which case the margins of the horny layer were worn through and a blackish deposit had accumulated under the horny layer.

In the second case it was related by the owner that his snake was seriously ill and that whitish material had accumulated in the ventral scales.

In this case there was a dermatitis, which caused a loosening of the horny layer from the underlying skin, with accumulation of powder under the horny layer. in addition the animal was suffering from a serious pneumonia.

Signs of disease which can be recognised by the owner can be divided into specific ones and a range of nonspecific signs.

Examples of specific signs are:

burns, bites, other trauma (for instance if a tortoise has fallen from a balcony), purulent material covering the eye, protrusion of the cloaca, permanent erection of a copulatory organ, or even laceration of copulatory organ as may occur in terrapins.

Examples of nonspecific or rather more general signs are:

not eating, listlessness, illthrift, emaciation. Not eating for instance may be caused by a wide range of causes and can even be completely normal. Not eating is normal in tortoises during hibernation. Not eating is normal in snakes during the process of moulting. Not eating is normal in pregnant female boas (snakes) from some days or weeks after copulation until birth.

Not eating can be seen in tortoises kept free roaming on the floor of a room which is too cold (rectal temperature 18 degees C or less) , warming them up to 24-26 degrees C ''cures'' the animals. Not eating can be an expression of stress such as in snakes kept in a situation where there is lots of movement around them. We once had a boa who only started to eat wlhen his terrarium was placed in a bedroom, where there was only 30 minutes of sounds and movements per day.

Not eating can also be an expression of mouth rot, where the pain and discomfort of the animal prevent him from eating.

Not eating may be a sign of diseases of the stomach or ascarid worms. Not eating is seen in the protozoan infection amoebiasis, affecting the intestinal tract. Not eating is seen in snakes suffering from an inflammation of the brain caused by a virus infection.

These are just examples of underlying diseases with a rather nonspecific sign like non-eating, and there are many more causes. The same accounts for listlessness, illthrift, emaciation and other more general signs of disease.

One of the difficulties with some of the generalised signs is, as we have seen, that it may not give an indication whether an animal is ill or not. It is one of the more difficult problems to judge objectively that a reptile is in good health.

What are signs of good health?

The animal is alert, it pays attention to its surroundings and the events which happen there. A tortoise which has redrawn its head in the carapace, within a short time will protrude its head to explore the environment. Snakes will actively flick their tongue, and thus orientate themselves in their (new) surroundings. Lizards look around and explore the environment, usually they move very quickiy. If approached too closely some will however defend themselves and try to bite.

The animal is clean. The skin of tortoises, terrapins, snakes and lizards is flexible, smooth and clean, not only because of repeated shedding, but also because no faeces are adhering to the ventral base of the tail. In some species of snakes th e healthy skin is beautifully iridescent. The carapace of tortoises and terrapins is smooth and free of cracks. The horny layer has no loose rims and there is no dirt or algal growth adhering to the carapace.

The nutritional status is good, not too thin and not too fat. In tortoises the Jackson ratio can be applied. In snakes, the muscles along the spine are well developed and the dorsal processes of the vertebrae are well hidden between the muscular masses. In lizards the muscular masses over the pelvis and at the base of the tail must be rounded. If the processes of the pelvic bones can be seen, the animal is too thin.

Muscles are well developed and forceful. In tortoises and terrapins the legs are rounded. The skin covers the muscles of the legs without folds. A test for the muscular force in tortoises is to let them hang, the forelegs resting on your fingers. They should be able to hang in this position during at least one minute. In snakes, the tension of the abdominal muscles, especially, must be good. In lizards, the muscular masses of the legs are forceful, to enable quick and efficient movements.

Before the actual clinical diagnostic work starts, it must be recognised that an animal is ill. the initial signs of disease have to be noted by the owner. Of course there is a wide range in the ability of owners to recognise disease, and in addition this is influenced by the circumstances. It makes a great difference whether the animals are looked after almost the whole day, or that the owner is very busy and has just enough time to feed and clean his animals. It is the initiative of the owner to consult the veterinarian. As we have arrived in the veterinary surgery, I will try to stand next to the owner and observe the veterinarian performing the clinical diagnostic work, give indications about the possibilities, the doubts and the impossibilities.

Often the veterinarian is obviously confronted with an animal he is not completely familiar with. If he is wise, he confesses this and asks for details about the animal. It is some kind of a handicap if you don't know the species but the general opinion among veterinarians is that once you are confronted with a herptile patient and provided you are interested and trying to do your best and help the patient, there are so many similarities to the usual patients that an acceptable result can be expected. As an owner you may be startled if a vet does not the difference between a lizard and a salamander. In such cases the expectations are low that a reasonable clinical diagnosis is made.

The veterinarian has a certain, almost fixed routine in performing clinical examination Of patients.

First you will notice that he asks for the history. How long is the animal in your possession? In recently imported animals the vet has to be aware of diseases brought in with the animal. In old animals one may think of (slowly) progressing diseases of the organs or ageing.

Has the patient been alone or in a group? In isolated animals the vet realises him1self that there is less risk that infectious diseases are building up.

Influences of other an aimless such as competition for space or food can be ruled out.

If the patient is a member of a group, the vet will realise himself that other animals may be affected, this influences his decision about treatment. If for instance a diagnosis of hexamitiasis is made in a diseased terrapin, the vet will prescribe to treat every individual in the group.

Were any animmals brought in recently? Newly obtained animals may bring diseases with them and infect the other established inhabitants. It is especially important to judge whether a disease may be an infectious one. For instance protozoan flagellate infections or amoebiasis can spread rapidly in a group and affect the animals which were already in the collection.

Occasionally this question can give clues which seem to be conflicting. This is especially the case with viral encephalitis in snakes. In this disease there are two possibilities:

A newly purchased animal is a carrier of the virus and infects the snakes present in the colony. After five to eight weeks the animals which were present may start to show signs of disease affecting the central nervous system such as the brain and the spinal cord.

A newly purchased animalis in perfect health and is brought in group of snakes where carriers of the virus are present but which do not themselves exhibit symptoms of disease. Then the new, completely susceptible animal will be infected and develop the disease.

Is this the only animal which is ill? This question gives the vet some insight whether an epidemic is going on or whether there is an individual problem, not related to infectious diseases, but confined to the individual. What type of Vivarium is the animal living in? This question gives the vet clues about the degree of hygiene. Lizards kept in a terrarium with soil and plants are likely to build up parasitic infections (e.g. worms) as the terrarium will be cleaned less often. The same accounts for tortoises living on a lawn where worm eggs may be preserved and embryonate in the humid environment and for terrapins living in a pond, where not only worm eggs can survive, but where flagellates can swim from one cloaca to another.

A covering with coarse sand is especially risky as it may cause small cuts, which may become infected. This may lead to abscesses on the toes or inflammation of the oral mucosa because food may be covered with sand and micro-organisms and damage the soft lining of the mouth.

What is the environmental temperature in the vivarium? An optimal temperature ensures an optimal functioning of the digestion and other body functions, but also optimal defence mechanisms in the body. On one occasion we were confronted with boas (snakes) which had previously been suffering from lungworms. The animals were sold and the new owner kept them at 5 degrees C lower than before. It appeared that these animals were more susceptible to infections under these living conditions and that they all died of pneumonia within a few weeks.

In which way is water provided - dirty pots, or a running stream of clean water? This also gives the vet information about the hygiene. An owner which had long standing problems with Pseudomonas pneumonia among his snakes, got rid of the problem when he gave his animals water twice a week,removing the water tank during the intervals. Thus the water tank could become completely dry and the micro-organisms could no longer multiply. What food is given? The type of food gives clues about nutritional deficiencies. If lean meat is given to a red-eared terrapin it is likely to develop both vitamin A deficiency and calcium deficiency. Which disease becomes manifest is a matter of amount of vitamin A reserves present. Details about the sources of the food may be of importance. In most of the Netherlands, the soil is very poor in iodine. If food of the local market is given to tortoises or terrapins, goitre is likely to occur, unless a vitamin mineral preparation containing iodine is provided.

The preferred diet for tortoises is a varied diet. Many individuals like clover and leaves of the daisy family, as well as leaves and flowers of violets or pansies and many other plants. Access to some free range grazing is helpful. It is wonderful to look how clever your tortoise can discriminate between grass and other herbs growing between them. Cooked peas, lentils, beans, barley and unpolished rice and many types of food produce excellent and palatable foods. Just to give you an idea, I once had a Hermann's tortoise who liked peaches and avocados. It appeared that he was also fond of the complete commercial food for mynah birds, which have comparable preferences.

The quality of the food is of importance to the vet who has knowledge about the nutritional value of foodstuffs. Tortoises forced to live on the outer leaves of salad are likely to develop protein deficiency (this is because the proteins accumulated in the leaves during growth change in configuration and become more resistant to the digestive juice and to bacterial breakdown) and thus have less resistance to infections and other causes of disease. Recently we found that stressed crickets can suffer from an infection which makes them less palatable or even diminish their nutritional value.

Earthworms kept in larger quantities over a longer period in a small amount of earth, can more or less intoxicate each other. they become ill. This is recognised as the worms become pale due to the fact that their digestive tract is empty. Snakes, like garter snakes, eating these, may become sick, vomit or develop diarrhoea.

There are fairly definite indications that snakes whiclh breed frequently, may develop a calcium deficiency and thus produce deficient offspring. This is because of the use of calcium to produce a skeleton in the embryo. Tortoises lay calcareous eggs, tlhe shell of which consists for about 50% of calcium.

Thus reptiles in a reproductive phase of life are in need of large quantities of calcium.

The quantity of the food, of course, is important for the animals. Snakes fed larger quantities in prolonged intervals, are more likely to develop deficiencies than those which are fed small quantities at smaller intervals. This can be explained by the fact that the B vitamins are very quickly metabolised and thus that if the source of those vitamins, i.e. the prey animal, is offered with larger intervals, the animals are more likely to develop deficiencies. The vitamins of the B complex and vitamin C are not stored.

Only the fat soluble vitamins A, D3 and E are stored, enabling the animal to overcome periods of shortage in these vitamins.

What abnormal signs were noticed? The question is of importance to give indications about the organ(s) or systems which are affected.

We may suppose in a given case there were signs of respiratory problems this might indicate a pneumonia or an infection of the upper respiratory tract.

The experienced veterinarian however , might remember a case of swelling of the tracheal opening, resulting in respiratory distress, caused by an infection of the skin lining of the mouth (the oral mucosa). This was the case in a fungal (mycotic infection, affecting especially the tongue of a tortoise.

Over what period have abnormal signs been noted? The question reflects thoughts about the duration of diseases. Some diseases are very acute and need immediate veterinary attention. This may be the case in acute traumas, like a fall from a balcony. It may be of especial importance when an enteritis caused by amoeba is suspected. Then immediate treatment is imperative. If, however, an animal has been ill over a longer period of days, weeks or months, the hours or days before the actual consultation of a veterinarian are relatively less important. They must not be delayed, but if signs are, for instance, related to a given period of moulting, the consultation Carl eventually be postponed until the moment of maximal expression of the disease is present.

These examples stress the importance of exact, detailed information provided by the owner as a basis for further clinical examination by the veterinarian.

After the history of the animal (the anamnesis is collected, the actual procedure of clinical examination is performed. This is done along a fairly fixed routine, working from the head to the tail. The general body condition is estimated using the criteria we have mentioned before.

The vet will check the skin for the presence of parasites, bacterial or fungal infections, moulting problems, trauma, swellings or bulgings, abscesses.

Careful examination is of importance to reach a diagnosis as exact as possible.

An example is a red-eared terrapin of which the owner related that it was suffering from excessive loss of superficial parts of the soft skin. In addition the skin was somewhat weak and made a slimy impression. This enabled the vet to make a differentiation from superficial mycosis. Microscopic examination revealed the presence of protozoa (in this case hexamites) in the superficial layers of the skin. Therapy was in bathing the animal in a solution of ronidazole. In this case the diagnosis, based on the anamnesis was relatively easy , as it only required tlhe use of a microscope and knowledge of the structure and movements of this specific chelonian pathogen. The difficult thing was that the vet had to realise himself that the presence of the parasite in an unusual place (they normally act as pathogens in the intestinal tract and the kidneys) was of importance and could cause the symptoms.

As a second example I may bring forward a snake where the owner had seen weak swellings, he had punctured these, collected clear fluid which he examined himself, found only a few flattened cells and some rounded cells which were interpreted as lymphocytes. The conclusion of the owner was that these swellings were dilatations of lymph vessels. Such a detailed anamnesis is a challenge to the vet. In this case further clinical diagnostics were performed in that a contrast medium was injected into the swellings and on X-ray it could be seen that the fluid spread in a way blood vessels branch. It was confirmed that the swellings indeed were dilated lymph vessels. Now this is a rather exceptional diagnosis, where the contrast medium which is normally injected in the bloodstream, to discover changes in the kidneys, was injected in a different medium (the lymph fluid). On the basis of this diagnosis no therapy was induced as it is impossible to treat a widespread dilatation of lymph vessels.

In a third case lizards were found dead and the owner had noticed black areas, with a minute hole in the centre. The holes were present in the scales. He had realised that the same had occurred one year before, when crickets were left in the terrarium. In this case post mortem examination revealed a fungal infection of the affected areas, spreading through the body. Removal of the crickets from the terrarium and strict control of crickets left after feeding, solved the problem. It was concluded that hungry crickets try to feed on lizards and that by doing so, a fungus (mycotic infection was introduced. After the skin, the eyes were examined for , swellings, oedema, overfilling of blood vessels, exudates, accumulation of material under the eyelids (vitamin A deficiency in terrapins. Special attention is given to the eyes of snakes, as these are provided with spectacles, under which exudate may accumulate. The clinical examination can be extended with collecting material, microscopic examination of materials, cultivation, puncturing the spectacle space. Ophthalmoscopic examination of the eye can be of assistance. The ears are examined (not in snakes!) for mites hiding along the edges of the tympanic membrane and exudate present in the middle ear. Here too there is a nice example of an exact anamnesis presented by an owner , who had seen a small worm behind the tympanic membrane of his lizard. Closer examination under a stereo microscope confirmed the diagnosis.

The nostrils are examined next, for exudate, accumulation of material, proliferations.

Example: On one occasion a Testudo hermanni of some days old was presented with respiratory distress. At closer inspection the nostrils were found blocked by very fine peat. Removal of the material cleared the problem. The bedding was changed to pebbles and the problem was over. Mucus exuded from the nose however is usually indicated of an infectious condition.

The mouth is inspected for overgrowth of the beak, fractures, inflammations and others.

Then the mouth is opened. The skin lining the mouth (the mucosa) is inspected. The colour is assessed (paleness may indicate anaemia). Inflammations, trematodes, submucosal bleedings indicative of a bacterial sepsis are looked for. In snakes, on occasion whitish circumscribed accumulations of urates can be found, which enable a definite clinical diagnosis of gout. In tortoises irregularities of the mucosa of the tongue may indicate a herpes virus infection.

The tracheal opening is inspected for the presence of exudate, indicative of an inflammation of the trachea or the lungs. Swelling of the mucosa may also be present in cases of a tracheitis. Exudates are examined microscopically for helminth or worm eggs (nematodes, pentastomes) or larvae. Swabs may be taken for bacterial cultivation. Pathogenic bacteria are tested for sensitivity to antibiotics.

The respiratory system is examined. The respiration is assessed. The veterinary surgeon pays attention to a forced respiration, indicative of an extensive pneumonia. Forced inward and outward movements of the forelegs indicate a pneumonia in tortoises and terrapins. A great help to the clinical diagnosis for the vet is making X-ray photographs of the lung fields. Occasionally the anamnesis reveals that a terrapin is tilting to the right or the left side while swimming. In such cases cranio-caudal X-rays may reveal asymmetrical densities of one or both lungs. On other occasions terrapins have difficulties in diving, or in contrast to reach the surface of the water. In both cases this is indicative of a lung problem where the baroreceptors, which regulate the amount of air necessary to reach a specific weight of zero, are not functioning. Here too X-ray pictures are of importance to make a clinical diagnosis.

The heart and circulation are assessed. In snakes the heartbeat itself can sometimes be judged by palpation. Making an electrocardiogram can be of help in clinical diagnostics. Ultrasonic examination can give an insight into functional abnormalities of the heart (impossible in chelonians, due to the bony carapace).

Overfilling of peripheral blood vessels may indicate a malfunction of the circulation and this of the functioning of the heart.

Blood sampling is difficult and of restricted value.

The digestive tract is assessed. The oesophagus is inspected over the maximal length, depending on the anatomical situation. This enabled us once to make a diagnosis of tuberculosis of the oesophagus (swabbing and microscopic examination of the exudate from the ulcer) in a snapping turtle, fed on aquarium fishes, which suffered from tuberculosis.

The stomach is assessed. In snakes a bulging of the stomach may be seen in severe acute inflammations. In chelonians and lizards, signs like lack of appetite, vomiting, regurgitation of food may indicate an inflammation (gastritis). In green iguanas of about five years of age calcification of the mucosa of the stomach may lead to lack of appetite and vomiting. Foreign bodies such as stones, or catheters used for force feeding may be recognised on X-ray pictures.

The intestinal tract is assessed. In most cases this is very difficult. Lack of appetite is a sign of enteritis. Diarrhoea, eventually blood stained, is also indicative of enteritis. Overfilling of intestines with gases may lead to craniocaudal tilting of terrapins or to a generalised blowing up in snakes. Palpation in tortoises may reveal pebbles in the intestine or regional thickening of the intestine in snakes, due to amoebiasis. X-ray examination, eventually with the aid of contrast media, can be very elucidatory. Obstructions by stones and other materials may be found.

Of great importance is the examination of fresh faeces. The faeces are examined for the consistency, whether mucus or blood are mixed in. Microscopic examination of wet smears may reveal infections with flagellates, (lung) worms, tapeworms, coccidia, balantidia, more or less by accident an occasional Entamnoeba invadens (these should be cultivated) and others (confusion with pseudoparasites is possible).

Tne possibilities of the vet to assess the urinary system are restricted. The urine produced by the kidneys, flows to the cloaca and then may eventually (in chelonia and lizards) be collected in a urinary bladder, to be manipulated during its passage. This implies that the substance produced does not reflect the actual situation in the kidneys.

In Elapidae (cobra and mamba family of snakes), a specific neplnritis is known, causing a tremendous enlargement of the kidneys revealing microscopically an interstitial nephritis in the presence of multinucleate giant cells. In such cases the diagnosis (enlargement of the kidneys) is made by external inspection (swelling of the body) and by palpation.

Consequences of a chronic nephritis may be brought back to the original lesion. Decalcification of the carapace is an effect known to veterinarians as secondary renal hyperparathyroidism this leads to an enlargement of the parathyroids and an irreversible overproduction of its hormone. Examination of urine in chelonians is of importance to diagnose hexamitiasis of the kidneys. The hexamites live in the intestine and can invade both the urinary bladder and the kidneys, as these organs open into the cloaca. Hexamites are easy to recognise in the urineand it is known that these parasites cause a (sub) chronic nephritis. Thus finding hexamites in urine, in combination with decalcification of the carapace enables the diagnosis of renal hyperparathyroidism. The prognosis (outlook) depends on the duration of the disease: the longer the disease has developed the more serious the alterations are and the poorer the prognosis is. The urinary bladder is very difficult to examine. An urinary stone can be recognised On X-ray examination in an ill thriving lizard or tortoise. Surgery may be helpful in such situations.

Genital apparatuses either of the male or the female are difficult to examine. In the reproductive female the production of eggs can be examined by palpation, X-ray examination, endoscopy of by ultrasonography (ultrasound). In the female terrapin cloacoscopy, using the accessory bladders may be an alternative possibility. Especially ultrasonography in tortoises and terrapins using the inguinal excavation before the knee, is promising. The (central) nervous system can be examined. A difficulty is that direct spinal reflexes are prominent, thus mimicking a normal functioning of the nervous system to the owner or the inexperienced vet. At closer examination however, distinct overactivity of direct reflexes in cases of transverse lesion of the spinal cord, distal of the lesion may be noticed. In some cases muscular spasms were noticed distal of the transverse lesion in snakes. Pain stimuli exerted to the part caudally of the lesion obviously do not reach the brain.

Lameness and inabilities to swim in terrapins remains mostly unclear. In a Hermann's tortoise, which was reluctant to move, we found inflammation of many joints of the legs.

In cases of viral encephalitis, in snakes, the patient is completely disorientated and no longer interested in its surroundings.

An extension of manual and physical methods of clinical examination are:

Examination of faeces; this is of great importance in the case of intestinal parasites, be it helminths, flagellates, amoebae or coccidia and in cases of bacterial infections.

Collection and examination of blood. Blood can be readily collected from the coccigeal vein in the tail of tortoises, which runs dorsally of the vertebrae and thus is punctured from the dorsal side (in lizards and snakes, this vein is situated ventrally of the vertebrae). It is fairly difficult to collect blood from reptiles and knowledge ofnormal values is restricted. Thus the value of these examinations in clinical evaluation of disease processes has to be extended and a more detailed knowledge has to be obtained.

X-ray examination is of exclusive value in clinical diagnostics in reptiles to make diagnoses of skeletal deformities or fractures. In soft tissue diagnostics X-ray examination is of value in cases where digestive patency is through swallowing stones, fish bones etc, or pulmonary situations should be judged.

Endoscopy is of increasing value in judging the genital organs especially. Biopsies of materials can be of great value in diagnosing different kind of infections and tumours or inflammations.

Examination of swabs is of great value in diagnosing bacterial infections of, for instance, the trachea or the respiratory tract as a whole.

Examination of biopsies is especially of value in the diagnosing of tumours and inflammatory processes.

Although there are many restrictions in the clinical examination of reptiles, it is possible for the vet who is interested and is willing to invest some time, to gain experience. Extending along this line, the vet has the basic knowledge concerning diseases and disease processes to be able to judge what is going on in a specific individual and to estimate and judge the functioning of the main organ systems.

At the end of my presentation to end With a quotation, "I feel like a real Turtle".